Conventional shoring is made from stock steel tubing having a circular cross section of uniform thickness. The shoring frames and accessories are typically constructed by welding, or less desirably by mechanical fastening. The frames are cross-braced for assembly into support towers and the like. An example of such shoring, adopted for use with extendable frames, is illustrated in U.S. Pat. No. 3,190,405, issued June 22, 1965.
Aluminum has had some increasing use in the industry, although usually limited to special application scaffolding, flying shoring, or stationary joists. Aluminum is desirable because of its light weight and noncorrosiveness. However, its adaptation to some applications has required devising some particularly unique designs to realize the full potential of the advantages in its use.
For example, for medium-weight shoring applications, the large inventories of standardized complimentary equipment and accessories have not been compatible with the shoring frames constructed of aluminum rated to handle a reasonable compression loading. The aluminum frame legs were either too thick-walled, bulky and costly, or if sufficiently thin-walled were of too large a diameter and not adaptable to readily available standard accessories.
Additionally, welding of the aluminum causes technical problems in the de-rating of the columnar loading permissible due to the annealing effect of the welding in the construction of the aluminum frame.
Thus, it is an object of this invention to provide an aluminum shoring frame or the like that retains most of the advantages of the original steel equipment with the additional advantages of lightness and ease of handling resulting from the use of aluminum.
It is a further object to develop a shoring frame made primarily from an extrudable light-weight material of adequate strength and yet be competitively priced, given its advantages.
It is a still further object of the present invention to make maximum effective use of a minimum of material to minimize weight and material costs, without reducing load capacity.
Yet another object of the present invention is to provide a shoring frame structure which facilitates manufacturing by obviating the need for costly coping of strut to circular legs.
It is an additional object of the present invention to provide a shoring frame made from aluminum or similar light-weight material, which frame has a reasonable load capacity and yet is able to utilize existing standard equipment and accessories without specialized adaptors or the like.